NUCLEIC ACID IX THE CIRCULACION 769 



Suiiiiiiary 



Labelled sodiumphosphate is administered to rats inoculated with Jensen's 

 sarcoma. From the saicomate labelled desoxyribonvicleic acid is prepared. 



Labelled desoxy ribonucleic acid dissolved in physiological sodium chloi'ide 

 solution is injected into the circulation of the rat. After the lapse of 2 houi-s, an 

 appreciable part of the labelled phosphorus is found to be present in the liver, 

 more than %^ being located in the acid soluble fraction. 



The total labelled phosphorus content of the plasma makes out at the end of the 

 experiment only 2 per cent of the ^'-P content injected as labelled desoxyribonucleic 

 acid; % of the plasma ^-P is present in the free phosphate fraction. 



In experiments in which liver slices were incubated in bicarbonate Ringer 

 solution containing labelled desoxja'ibonucleic acid the phosphate group of more 

 than 2/g of the nucleic acid added was found to be split off in the course of 4 hours; 

 i/g of the total acid soluble ^-P being present in the free phosphate fraction of the 

 Ringer solution. 



Mabshak and Waxker found that after the injection of labelled chromatin 

 into the circulation of partially hepatectomized rats, the liver nuclei took up 

 much more ^^P than when labelled phosphate was injected. They found also that 

 in the first mentioned case the liver contains a much larger percentage of ^-P 

 than in the last mentioned one. The results described in this note suggests the 

 explanation that the accumulation of ^^p on the hver nuclei after injection of label- 

 led chromatin, is mostly or who 11 .y due to the intrusion of labelled phosphate split 

 off from the nucleic acid molecules present in the chromatin into the liver nuclei. 



49 Hevesy 



